The discharge for plasma Stark shift measurement and results for He I 706.522 nm line

•Description of new discharge with peak electron densities higher than 7×1023 m−3.•New method for spectral line shift measurements presented.•Stark shifts for He I 706.522 nm for several electron densities measured.•Stark shifts for He I 706.522 nm compared with theoretical and experimental results.•Derived formula for Stark shifts of the He I 706.522 nm line dependence upon electron density.

We present results of Stark shift measurements for He I 706.522 nm (1s2p 3P20-1s3s 3S1 and 1s2p 3P10-1s3s 3S1) lines using newly constructed pulsed arc generated at the pressure of two hundreds of milibars of helium with small admixture of hydrogen. Plasma electron number density in the range (0.5-7.0)×1023 m−3 was measured from the wavelength separation between the allowed He I 447.1 nm (2p 3P0-4d 3D) line and its forbidden component (2p 3P0-4d 3F0), while the electron temperature in the range (15,000-20,000) K was determined from the relative intensities of Si II lines using the Boltzmann plot technique. New Stark shift measurement technique was demonstrated using line shape recording of several He I lines. The shift results for He I 706.522 nm line so favorably compare with earlier lower density experimental data that best fit formula is recommended for plasma diagnostic purposes.